Atomic Beam Studies of Silver-109m and Cesium-138

Abstract

Atomic beam magnetic resonance techniques have been used to investigate the properties of the 41-second isomeric state of silver-109 and the 32-minute ground state of the fission product cesium-138. A description of the apparatus and of the atomic beam method for the determination of nuclear moments is given. The results obtained for silver-109m are: I= 7/2 a(2S1/2) = 9477±13 Mc/sec μ1 (uncorrected) = 4.31±0.04 nuclear magnetons 109Δ109m = -(1.1±1.2)%. The value of the moment confirms that the proton configuration is (g9/2)^-3 7/2. In the course of this experiment, multiple quantum Zeeman transitions were observed between levels in both the F = I + 1/2 and F = I - 1/2 hyperfine multiplets. The results obtained for cesium-138 are: I =3 Δv = 1650 +650 -250 Mc/sec |μI| (uncorrected)= 0.45 +0.18 -0.07 nuclear magnetons. For these experiments simultaneous detection of both the resonant and thrown out portions of the beam was used for the first time in this laboratory.